This noise started today. It’s a light knocking noise that only happens when I let off the gas. If I’m applying torque to the wheels, no knocking. The second I decelerate or even shift (manual) it knocks. Not rhythmic at all - pretty random once it starts and it always stops when I accelerate. Also does not seem to be associated with the suspension since regardless of large bumps or small, it doesn’t knock - unless I’m decelerating at the same time.

Just had new rotors and pads installed on Sunday, but they've felt great. I did have a red light sneak up on me today so I stomped them pretty good - knocking problem arose about 10 miles later on the highway.

I’m already set up to bring it in to the dealer tomorrow, but 80-100 miles until then has me a little worried. And I hate when my car makes noises that it shouldn’t. Thanks for any ideas on the source.

 

Knock? Or a 'bang', like metal to metal contact?
If it's a "knock", it could be as easy as engine mounts, or loose suspension hardware.

- Erik

 

It doesn’t sound like metal on metal, but it’s hard to tell at highway speeds. I just hope it doesn’t get worse tomorrow...

 

I'd start with engine mounts; when you shift, the weight transition from loading and unloading the transmission can shift the powertrain.
Suspension bushings and other front end joining components is where I'd start.

- Erik

 

Given that you just replaced the front pads and rotors, perhaps the anti-rattle hardware for the pads were not installed properly. That might be a reasonable place to start.....

 

I think I have the same sound with my 2011. I get it when letting off the gas abruptly or when i accelerate. It is for sure coming from the passenger side of the car. Almost like something is hitting the firewall.

 

That's exactly what mine sounded like, but never accelerating.

My noise has now disappeared. Heard it briefly when I pulled out of the driveway this morning, but 80 miles later, after a drive with the service manager at MINI and after putting it up on the lift to check for anything loose/broken and everything appears fine. I'm hoping that I ran over something and maybe it just got stuck and is now unstuck. Or maybe the brake dude left a tool in there (you know, like doctors sometimes leave stuff in people during surgery) and it's now worked it's way out.

All joking aside, I hate random noises that are intermittent. And also hate not knowing what caused it.

 

I had a similar noise whenever I started from a stop or changed directions (fwd to bkwd) and when I got home tonight there was an oil slick under the right rear side and a bunch of oil that ran out to my pass front wheel. I'm thinking I blew an axel seal.

 

Turns out it was the timing chair tensioner that caused the major oil leak, three chain guides, tensioner and chain being replaced. Though the axel seal was bad as well. Thank you CPO.